<?php

namespace components;

use Yii;
use yii\base\Exception;
use yii\helpers\Json;

class Curl
{
	/**
	 * @var string
	 * * Holds response data right after sending a request.
	 */
	public $httpType = 'http';

	/**
	 * @var string|boolean
	 * Holds response data right after sending a request.
	 */
	public $response = null;
	/**
	 * @var null|integer
	 * Error code holder: https://curl.haxx.se/libcurl/c/libcurl-errors.html
	 */
	public $errorCode = null;
	/**
	 * @var null|string
	 * Error text holder: http://php.net/manual/en/function.curl-strerror.php
	 */
	public $errorText = null;
	/**
	 * @var integer HTTP-Status Code
	 * This value will hold HTTP-Status Code. False if request was not successful.
	 */
	public $responseCode = null;
	/**
	 * @var string|null HTTP Response Charset
	 * (taken from Content-type header)
	 */
	public $responseCharset = null;
	/**
	 * @var int HTTP Response Length
	 * (taken from Content-length header, or strlen() of downloaded content)
	 */
	public $responseLength = -1;
	/**
	 * @var string|null HTTP Response Content Type
	 * (taken from Content-type header)
	 */
	public $responseType = null;
	/**
	 * @var array|null HTTP Response headers
	 * Lists response header in an array if CURLOPT_HEADER is set to true.
	 */
	public $responseHeaders = null;
	/**
	 * @var array HTTP-Status Code
	 * Custom options holder
	 */
	protected $_options = [];
	/**
	 * @var array
	 * Hold array of get params to send with the request
	 */
	protected $_getParams = [];
	/**
	 * @var array
	 * Hold array of post params to send with the request
	 */
	protected $_postParams = [];
	/**
	 * @var resource|null
	 * Holds cURL-Handler
	 */
	public $curl = null;
	/**
	 * @var string
	 * hold base URL
	 */
	protected $_baseUrl = '';
	/**
	 * @var array default curl options
	 * Default curl options
	 */
	protected $_defaultOptions = [

		CURLOPT_USERAGENT      => 'Yii2-Curl-Agent',
		CURLOPT_TIMEOUT        => 10,
		CURLOPT_CONNECTTIMEOUT => 10,
		CURLOPT_RETURNTRANSFER => true,
		CURLOPT_HEADER         => true,

		CURLOPT_SSL_VERIFYPEER => false,
		CURLOPT_SSL_VERIFYHOST => 2,
	];
	// ############################################### class methods // ##############################################
	/**
	 * Start performing GET-HTTP-Request
	 *
	 * @param string  $url
	 * @param boolean $raw if response body contains JSON and should be decoded
	 *
	 * @return mixed response
	 */
	public function get($url, $raw = true)
	{
		$this->_baseUrl = $url;
		return $this->_httpRequest('GET', $raw);
	}
	/**
	 * Start performing HEAD-HTTP-Request
	 *
	 * @param string $url
	 *
	 * @return mixed response
	 */
	public function head($url)
	{
		$this->_baseUrl = $url;
		return $this->_httpRequest('HEAD');
	}
	/**
	 * Start performing POST-HTTP-Request
	 *
	 * @param string  $url
	 * @param boolean $raw if response body contains JSON and should be decoded
	 *
	 * @return mixed response
	 */
	public function post($url, $raw = true)
	{
		$this->_baseUrl = $url;
		return $this->_httpRequest('POST', $raw);
	}
	/**
	 * Start performing PUT-HTTP-Request
	 *
	 * @param string  $url
	 * @param boolean $raw if response body contains JSON and should be decoded
	 *
	 * @return mixed response
	 */
	public function put($url, $raw = true)
	{
		$this->_baseUrl = $url;
		return $this->_httpRequest('PUT', $raw);
	}
	/**
	 * Start performing PATCH-HTTP-Request
	 *
	 * @param string  $url
	 * @param boolean $raw if response body contains JSON and should be decoded
	 *
	 * @return mixed response
	 */
	public function patch($url, $raw = true)
	{
		$this->_baseUrl = $url;
		$this->setHeaders([
			'X-HTTP-Method-Override' => 'PATCH'
		]);
		return $this->_httpRequest('POST',$raw);
	}
	/**
	 * Start performing DELETE-HTTP-Request
	 *
	 * @param string  $url
	 * @param boolean $raw if response body contains JSON and should be decoded
	 *
	 * @return mixed response
	 */
	public function delete($url, $raw = true)
	{
		$this->_baseUrl = $url;
		return $this->_httpRequest('DELETE', $raw);
	}
	/**
	 * Set curl option
	 *
	 * @param string $key
	 * @param mixed  $value
	 *
	 * @return $this
	 */
	public function setOption($key, $value)
	{
		//set value
		if (array_key_exists($key, $this->_defaultOptions) && $key !== CURLOPT_WRITEFUNCTION) {
			$this->_defaultOptions[$key] = $value;
		} else {
			$this->_options[$key] = $value;
		}
		//return self
		return $this;
	}
	/**
	 * Set get params
	 *
	 * @param array $params
	 * @return $this
	 */
	public function setGetParams($params)
	{
		if (is_array($params)) {
			foreach ($params as $key => $value) {
				$this->_getParams[$key] = $value;
			}
		}
		//return self
		return $this;
	}
	/**
	 * Set get params
	 *
	 * @param array $params
	 * @return $this
	 */
	public function setPostParams($params)
	{
		if (is_array($params)) {
			$this->setOption(
				CURLOPT_POSTFIELDS,
				http_build_query($params)
			);
		}
		//return self
		return $this;
	}
	/**
	 * Set raw post data allows you to post any data format.
	 *
	 * @param mixed $data
	 * @return $this
	 */
	public function setRawPostData($data)
	{
		$this->setOption(
			CURLOPT_POSTFIELDS,
			$data
		);
		//return self
		return $this;
	}
	/**
	 * Set get params
	 *
	 * @param string $data
	 * @return $this
	 */
	public function setRequestBody($data)
	{
		if (is_string($data)) {
			$this->setOption(
				CURLOPT_POSTFIELDS,
				$data
			);
		}
		//return self
		return $this;
	}
	/**
	 * Get URL - return URL parsed with given params
	 *
	 * @return string The full URL with parsed get params
	 */
	public function getUrl()
	{
		if (Count($this->_getParams) > 0) {
			return $this->_baseUrl.'?'.http_build_query($this->_getParams);
		} else {
			return $this->_baseUrl;
		}
	}
	/**
	 * Set curl options
	 *
	 * @param array $options
	 *
	 * @return $this
	 */
	public function setOptions($options)
	{
		$this->_options = $options + $this->_options;
		return $this;
	}
	/**
	 * Set multiple headers for request.
	 *
	 * @param array $headers
	 *
	 * @return $this
	 */
	public function setHeaders($headers)
	{
		if (is_array($headers)) {
			//init
			$parsedHeader = [];
			//collect currently set headers
			foreach ($this->getRequestHeaders() as $header => $value) {
				array_push($parsedHeader, $header.':'.$value);
			}
			//parse header into right format key:value
			foreach ($headers as $header => $value) {
				array_push($parsedHeader, $header.':'.$value);
			}
			//set headers
			$this->setOption(
				CURLOPT_HTTPHEADER,
				$parsedHeader
			);
		}
		return $this;
	}
	/**
	 * Set a single header for request.
	 *
	 * @param string $header
	 * @param string $value
	 *
	 * @return $this
	 */
	public function setHeader($header, $value)
	{
		//init
		$parsedHeader = [];
		//collect currently set headers
		foreach ($this->getRequestHeaders() as $headerToSet => $valueToSet) {
			array_push($parsedHeader, $headerToSet.':'.$valueToSet);
		}
		//add override new header
		if (strlen($header) > 0) {
			array_push($parsedHeader, $header.':'.$value);
		}
		//set headers
		$this->setOption(
			CURLOPT_HTTPHEADER,
			$parsedHeader
		);
		return $this;
	}
	/**
	 * Unset a single header.
	 *
	 * @param string $header
	 *
	 * @return $this
	 */
	public function unsetHeader($header)
	{
		//init
		$parsedHeader = [];
		//collect currently set headers and filter "unset" header param.
		foreach ($this->getRequestHeaders() as $headerToSet => $valueToSet) {
			if ($header !== $headerToSet) {
				array_push($parsedHeader, $headerToSet.':'.$valueToSet);
			}
		}
		//set headers
		$this->setOption(
			CURLOPT_HTTPHEADER,
			$parsedHeader
		);
		return $this;
	}
	/**
	 * Get all request headers as key:value array
	 *
	 * @return array
	 */
	public function getRequestHeaders()
	{
		//Init
		$requestHeaders = $this->getOption(CURLOPT_HTTPHEADER);
		$parsedRequestHeaders = [];
		if (is_array($requestHeaders)) {
			foreach ($requestHeaders as $headerValue) {
				list ($key, $value) = explode(':', $headerValue, 2);
				$parsedRequestHeaders[$key] = $value;
			}
		}
		return $parsedRequestHeaders;
	}
	/**
	 * Get specific request header as key:value array
	 *
	 * @param string $headerKey
	 *
	 * @return string|null
	 */
	public function getRequestHeader($headerKey)
	{
		//Init
		$parsedRequestHeaders = $this->getRequestHeaders();
		return isset($parsedRequestHeaders[$headerKey]) ? $parsedRequestHeaders[$headerKey] : null;
	}
	/**
	 * Unset a single curl option
	 *
	 * @param string $key
	 *
	 * @return $this
	 */
	public function unsetOption($key)
	{
		//reset a single option if its set already
		if (isset($this->_options[$key])) {
			unset($this->_options[$key]);
		}
		return $this;
	}
	/**
	 * Unset all curl option, excluding default options.
	 *
	 * @return $this
	 */
	public function unsetOptions()
	{
		//reset all options
		if (isset($this->_options)) {
			$this->_options = [];
		}
		return $this;
	}
	/**
	 * Total reset of options, responses, etc.
	 *
	 * @return $this
	 */
	public function reset()
	{
		if ($this->curl !== null) {
			curl_close($this->curl); //stop curl
		}
		//reset all options
		if (isset($this->_options)) {
			$this->_options = [];
		}
		//reset response & status params
		$this->curl = null;
		$this->errorCode = null;
		$this->response = null;
		$this->responseCode = null;
		$this->responseCharset = null;
		$this->responseLength = -1;
		$this->responseType = null;
		$this->errorText = null;
		$this->_postParams = [];
		$this->_getParams = [];
		return $this;
	}
	/**
	 * Return a single option
	 *
	 * @param string|integer $key
	 * @return mixed|boolean
	 */
	public function getOption($key)
	{
		//get merged options depends on default and user options
		$mergesOptions = $this->getOptions();
		//return value or false if key is not set.
		return isset($mergesOptions[$key]) ? $mergesOptions[$key] : false;
	}
	/**
	 * Return merged curl options and keep keys!
	 *
	 * @return array
	 */
	public function getOptions()
	{
		return $this->_options + $this->_defaultOptions;
	}
	/**
	 * Get curl info according to http://php.net/manual/de/function.curl-getinfo.php
	 *
	 * @param null $opt
	 * @return array|mixed
	 */
	public function getInfo($opt = null)
	{
		if ($this->curl !== null && $opt === null) {
			return curl_getinfo($this->curl);
		} elseif ($this->curl !== null && $opt !== null) {
			return curl_getinfo($this->curl, $opt);
		} else {
			return [];
		}
	}
	/**
	 * Performs HTTP request
	 *
	 * @param string  $method
	 * @param boolean $raw if response body contains JSON and should be decoded -> helper.
	 *
	 * @throws Exception if request failed
	 *
	 * @return mixed
	 */
	protected function _httpRequest($method, $raw = false)
	{
		//set request type and writer function
		$this->setOption(CURLOPT_CUSTOMREQUEST, strtoupper($method));
		//check if method is head and set no body
		if ($method === 'HEAD') {
			$this->setOption(CURLOPT_NOBODY, true);
			$this->unsetOption(CURLOPT_WRITEFUNCTION);
		}
		//setup error reporting and profiling
		if (YII_DEBUG) {
			Yii::trace('Start sending cURL-Request: '.$this->getUrl().'\n', __METHOD__);
			Yii::beginProfile($method.' '.$this->_baseUrl.'#'.md5(serialize($this->getOption(CURLOPT_POSTFIELDS))), __METHOD__);
		}
		/**
		 * proceed curl
		 */
		$curlOptions =  $this->getOptions();
		$this->curl = curl_init($this->getUrl());
		curl_setopt_array($this->curl, $curlOptions);
		$response = curl_exec($this->curl);
		//check if curl was successful
		if ($response === false) {
			//set error code
			$this->errorCode = curl_errno($this->curl);
			$this->errorText = curl_strerror($this->errorCode);
			switch ($this->errorCode) {
				// 7, 28 = timeout
				case 7:
				case 28:
					$this->responseCode = 'timeout';
					return false;
					break;
				default:
					return false;
					break;
			}
		}
		//extract header / body data if CURLOPT_HEADER are set to true
		if (isset($curlOptions[CURLOPT_HEADER]) && $curlOptions[CURLOPT_HEADER]) {
			$this->response = $this->_extractCurlBody($response);
			$this->responseHeaders = $this->_extractCurlHeaders($response);
		} else {
			$this->response = $response;
		}
		// Extract additional curl params
		$this->_extractAdditionalCurlParameter();
		//end yii debug profile
		if (YII_DEBUG) {
			Yii::endProfile($method.' '.$this->getUrl().'#'.md5(serialize($this->getOption(CURLOPT_POSTFIELDS))), __METHOD__);
		}
		//check responseCode and return data/status
		if ($this->getOption(CURLOPT_CUSTOMREQUEST) === 'HEAD') {
			return true;
		} else {
			$this->response = $raw ? $this->response : Json::decode($this->response);
			return $this->response;
		}
	}
	/**
	 * Extract additional curl params protected class helper
	 */
	protected function _extractAdditionalCurlParameter ()
	{
		/**
		 * retrieve response code
		 */
		$this->responseCode = curl_getinfo($this->curl, CURLINFO_HTTP_CODE);
		/**
		 * try extract response type & charset.
		 */
		$this->responseType = curl_getinfo($this->curl, CURLINFO_CONTENT_TYPE);
		if (!is_null($this->responseType) && count(explode(';', $this->responseType)) > 1) {
			list($this->responseType, $possibleCharset) = explode(';', $this->responseType);
			//extract charset
			if (preg_match('~^charset=(.+?)$~', trim($possibleCharset), $matches) && isset($matches[1])) {
				$this->responseCharset = strtolower($matches[1]);
			}
		}
		/**
		 * try extract response length
		 */
		$this->responseLength = curl_getinfo($this->curl, CURLINFO_CONTENT_LENGTH_DOWNLOAD);
		if((int)$this->responseLength == -1) {
			$this->responseLength = strlen($this->response);
		}
	}
	/**
	 * Extract body curl data from response
	 *
	 * @param string $response
	 * @return string
	 */
	protected function _extractCurlBody ($response)
	{
		return substr($response, $this->getInfo(CURLINFO_HEADER_SIZE));
	}
	/**
	 * Extract header curl data from response
	 *
	 * @param string $response
	 * @return array
	 */
	protected function _extractCurlHeaders ($response)
	{
		//Init
		$headers = [];
		$headerText = substr($response, 0, strpos($response, "\r\n\r\n"));
		foreach (explode("\r\n", $headerText) as $i => $line) {
			if ($i === 0) {
				$headers['http_code'] = $line;
			} else {
				list ($key, $value) = explode(':', $line, 2);
				$headers[$key] = ltrim($value);
			}
		}
		return $headers;
	}
}